Telephone



(No Model.)

- 'J. H. IRWIN.

TELEPHONE.

No. 430,128. Patented June 17, 1890.

JEZ tteJ't In Ventar:

UNITED STATES PATENT OFFICE.

JOHN H. IRWIN, OF MORTON, PENNSYLVANIA.

TELEPHONE.

SPECIFICATION forming part of Letters Patent No. 430,128, dated June 17,1890.

Application filed April 24, 1880. Serial No. 8,323. (No model.) I

To all whom it may concern.-

Be it known that I, JOHN H. IRWIN, of Morton, in the county of Delawareand State of Pennsylvania, have invented a new and useful Improvement inTelephones, whereof the following is a full and exact description.

This invention relates to that class of telephones wherein there is adiaphragm which bears one electrode and has another electrode held incontact therewith; and it consists in mounting said second electrodeupon an adjustable elastic weighted arm, which is free at one end andinsulated as to said diaphragm and its electrode.

It is to be understood that the instrument herein shown is designed foruse as a transmitter in any ordinary telephonic circuit, and any propertelephonic receiver may be employed therewith.

That others may fully understand my invention, I will particularlydescribe it, havin g reference to the accompanying drawings, wherein-Figure 1 represents my invention in sectional perspective. Fig. 2 is anenlarged elevation of the electrode and. diaphragm.

The transmitter 13 is composed of an electrode 71, provided with acontact-surface of platinum or other suitable material mounted upon theend of an elastic reed t', and weighted at the free end, as shown at k.The reed is fixed at its rear end and the electrode his put in thecircuit-by elastic connection with said reed if the same is composed ofa conducting material, or by a separate conductor if the reed iscomposed of a non-conducting material. The elasticity of the reed ttends to lift the electrode, and the superimposed weight k is sufficientto overcome the elasticity of the reed and maintain the proper contactof the electrodes. This contact is therefore the effect of the constantand unvarying force of gravity, and the counteracting force of thespring is a diiferential quantity, capable of the most delicateadjustment by regulating the adjusting-screw p or other proper means forsecuring the proper initial pressure. The

electrode h is in contact with the electrode t, which is preferablyformed of gas-carbon mounted upon a receiver of sound-waves or diaphragm'm. The fixed end of the reed t' is also secured to the surface of thediaphragm m, and therefore no disturbance of relation between theelectrodes will then occur if the diaphragm m shall from any causebecome displaced more or less upon its support.

. It is necessary to interpose between the fixed end of the reed and itssupport upon the diaphragm m a cushion of some non-conducting substancelike india-rubber, which is also elastic and has great power to absorbvibrations. I therefore mount the fixed end of the reed 1' upon a blockof india-rubber n, and secure it there by a bolt p, which passesdownward through the reed, block at, and diaphragm on into a nut orother fastening.

All matters originally shown and described in thisapplication, exceptingthat relating specifically to the mounting of both electrodes upon thediaphragm, are disclaimed, because they form the subject of anotherpatent.

Having described my invention, what I claim as new is 1. In atelephone-transmitter,a diaphragm having bot-h electrodes mounted uponit, one electrode being mounted directly upon such diaphragm and theother electrode beiieg secured to an elastic arm mounted upon saiddiaphragm, substantially as described.

2. In a telephone-transmitter,a diaphragm having both electrodes mountedupon it, one electrode of carbon being mounted directly upon suchdiaphragm andthe other electrode being secured to an elastic arm mountedupon a block fastened to said diaphragm, substantially as described.

3. In a telephone-transmitter, the combination, with a diaphragmcarrying one electrode, of an insulating-block fastened on saiddiaphragm and moving with the same, and carrying an elastic arm bearingthe other electrode, the tension of said arm being op posed by a weighton the same, substantially as set forth.

4. In a telephone-transmitter, an insulating-block secured to thediaphragm and carrying an elastic arm, to which is secured an electrodemaintained in contact with, another electrode mounted directly upon thediaphragm.

J. H. IRWIN. Witnesses:

R. D. 0. SMITH, KINGSTON GODDARD.

